Matthew Cruz, a 17-year-old who was seriously injured after the bus in which he was riding crashed into an overpass spanning Soldiers Field Road Saturday is “alert and aware of what’s happening,” but remains in critical condition, according to a statement released by his family Tuesday. More than 30 people were hospitalized after a bus carrying Philadelphia high school students who had just toured Harvard University slammed into the Western Avenue bridge. Cruz, who is being treated at Boston Medical Center, was the most seriously injured. State Police have said they are waiting for completion of investigations before deciding whether to press charges against the bus driver.